title: Simple enzymatic assay for determining cholesterol concentrations in bile.
abstract: We use bilirubin oxidase (EC 1.3.3.5) to remove interference by bilirubin in the assay of cholesterol concentration in bile by standard enzymatic methods. Samples are treated for 10 min with nonlimiting amounts of bilirubin oxidase to form biliverdin from bilirubin before the reagent for cholesterol is added. The relatively small interference by biliverdin is easily eliminated by use of sample blanks. The method is simple, convenient, and not hampered by the "chromogen oxidase" activity (the inherent ability of bilirubin oxidase to oxidize some chromogens) that plagues other assays of this type. Using this assay, we have accurately and precisely determined the concentration of cholesterol in bile. Such elimination of bilirubin will also be useful in assays of other biliary constituents or constituents of urine or icteric plasma.
authors.affiliation: Department of Animal Science, Iowa State University, Ames 50011.
authors.forename: C M
authors.initials: CM
authors.lastname: Luhman
authors.forename: S T
authors.initials: ST
authors.lastname: Galloway
authors.forename: D C
authors.initials: DC
authors.lastname: Beitz
mesh_terms: D000818:Animals; D001646:Bile / Q000032:analysis*; D001664:Biliverdine; D002784:Cholesterol / Q000032:analysis* / Q000097:blood / Q000652:urine; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; D013552:Swine
chemical_list: D002784:Cholesterol; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C042401:bilirubin oxidase; D001664:Biliverdine